Ground clamp



Jan. 2, 1934. L MANGlN 1,942,341

GROUND CLAMP Filed Jan. 9, 1930 f MIIIIIIII l Ja Q8 Patented 2, 1934 UNITED STATES GROUND CLAMP James Mangln, New Brunswick, N. J., assigner to New Brunswick Electric Supply Company, New Brunswick, N. J., a corporation of New Jersey Application January 9, 1930.` lSerial No. 419,598

3 Claims.

The present invention relates to ground clamps such as are used in the installation of electric wiring in buildings to ground to a water pipe and the like the lead-in conduit and the conductor or conductors carried thereby and, particularly, relates to improvements in said ground clamps whereby universal adjustment of the clamp may bevmade to connect it to a grounding pipe and an electric conduit regardless of the direction of l0 approach of the conduitrelative to the ground-- still provide a very rigid and eicient connection j between the conduit and the conductor to be grounded and the grounding pipe.

' Another object is to provide a clamp which may be attached to pipes oi various diameters and which is provided with means for adjusting itself to the particular diameter of pipe used without taking the clamp apart.

A further object is to provide a ground clamp in .which the clamping means serves to hold the various elements of the clamp in rigid assembled relation and simultaneously provides a direct emcient electrical connection between the grounding pipe and the conductor to be grounded.

A still further object is to provide a clamp in.

which the clamping means serves to hold the various elements of the clamp in rigid assembled relation after the adjustments are made and simultaneously provides eiiicient electrical connections between the grounding pipe, the conduit and Athe conductor to be grounded.

' Other objects and advantages will appear more fully hereinafter from the following detailed description taken together with the accompanying drawing, in which:

Fig. 1 is an end view of my device clamped to a grounding pipe; y

Fig. 2 is asectional view thereof taken along the line 2--2 of Fig. 1;

Fig. 3 is a perspective view of the conduit-receiving element;

Fig. 4 is a perspective view of the clamp ele- 55 ment;

Fig. 5 is a sectional view oi a modication of the assembled clamp; and l Fig. 6 is a perspective view of a preferred terminal lug used in connection with my device.

Referring to Figs. 1 to 4, the device ncomprises 60 the clamping element 1 which is provided with a circular base portion 1a having a pair of diametrically-opposed recesses 8. Extending from y the base 1 a and integral therewith are a pair of uprights 2 disposed in parallel relation which 05 are joined on one side by a wall 3 extending between them and holding them in spaced relation. The other side is left open to form a recess 4 combining with the recess 8 to provide for the reception of the S-bolt 15, as will be explained more fully hereinafter. The recesses ,8 are pro-l vided for the reception of the shanks oi' a U-bolt, as shown in the modification in Fig. 5.- Each upright 2 has al U-shaped recess extending therein which forms a pair of jaws for gripping the pipe 1'7 and each jaw is provided with portions 5, 6 and '7 which in the present instance are made up of arcuous portions of surfaces of cylinders lof various diameters so that no matter what the diameter of the pipe 17 may be, it may be placed' 80 in the jaw and still make eiiicient contact with the'jaws. For example, as shown in Fig. 1, the diameter of the pipe 17 is such that it contacts .with the portions 6 of the jaws; if the pipe were of a smaller diameter, it would be seated in the portion 5 and if larger in-diameter,` would contact with the portions`7. In this way, the device may be clamped to a pipe of any diameter within the constructional limitsl of the device. The conduit-receiving element 9 is provided to 90 co-act with the base 1a` of the clamping element 1 and is also circular in form and of the same diameter as.the base 1a, so that it may coincidetherewith when assembled, as shown in Figs. 1 and 2. It is provided with a central opening14 through which the shank of the S-bolt is adapted to pass to receive the terminal lug 19 to which is' attached the conductor 23 extending from/the conduit 24'. Integral with the circular or disk portion of the element 9 is a cylindrical portion 100 10 having its axis perpendicular vto the axis of the disk and 'is threaded at^11 for the reception of the electrical conduit to be grounded which carries the conductor or conductors 23 also to be grounded. Crescent-shaped recesses 12 are provided so that theI element may be rotated about its axis when a U-bolt is used to clamp the pipe,

the shanks of the U-bolt extendingthrough these recesses, (Fig. 5). The clamping element 1 and the conduit-receiving element 9 are held together 110 in cooperating relation by means of the S-bolt modication, the element 9 may still be rotated (Figs.\1 and 2) which yserves the purpose of about the'bolt 29 without interfering with the holding the assembled clamp rigidly to the pipe shanks 26 of the bolt 25, since clearance is prol'l Simultaneously and provides electrical convided Afor them by means of the recesses 12. The nections for the terminal lug 19 by means o1' the same yadjustments may be made as when the S- washer 18 and the nut 18. The conduit 24 bolt is used,

is grounded through element 9 and the clamping/ In Fig. 6, I have shown an improved terminal element 1. When the 1111i? 18 iS dIaWn up and lug for connecting the conductor 23 tothe shank tightened on the shank 16, the entire assembly of the s-bolt in Fig. 2 or the bo1t 28 in Fig. 5. becomes rigid and provides an efficient electrical The lug .1s stamped out of some conducting maconnection between the conductor, the conduit, fterial, preferably copper, and is provided With a and the grounding pipe- T0 Connect the Clamp pair of holes '20 and a` hole 22 for the reception t0 21 Pipe, the S-bOlt 15 iS inserted in the Opening of the conductor 23 as indicated. When the hole 14 of the element 9 land the Clamping element 1 22 is cut out, the material which is removed from iS placed in .illXtapoSitOn With the element 9 S0 the hole is not cut away completely but is turned thatihe Shank 0f the bolt paSSeS through the up in the form of triangular prongs 21 which are reCeSS 4 and the uplghts 2 are then placed adapted to engage the conductor 23 when it is again-St the pipe S0 that the pipe may be Seated passed through the holes 20. The conductor is in thecurved portions 5, 6 0r 7, depending 0n its inserted by passing one end of it' through one'iof diameter and the hook portion'of the S-bolt iS the holes 2o and bending it around the portions made to engage the pipe and then the conduit is 21 which are normally vertiea1 and then insert- Screwed into the Cylindrieal Portion 10 0f the ing it into the other hole 20. The prongs 21 are element 9 and the conductor 23 which extends then bem; over the conductor and, in this.. way, from the Conduit 24 1S attaehed'to the Shank 16 a rigid and eicient contact is made between the 0f the bOl'l 15 by means Of the lterminal lug 19 lug and conductor and a soldering operation is The washer 18' is then placed on the shank to provide a more rigid connection of the terminal 'lug and the nut 18 is then drawn up and tightened against the washer 18'. It will be seen that this arrangement of parts provides an adjustment of the clamp while it is attached to the pipe 17 to receive the conduit 24' from any direction relative to the direction of the pipe. For example, in Fig. 2, the conduit 24' is shown as approaching the pipe 17 from the right, and

parallel to it. If the conduit approached the pipe from the left, all that would be necessaryy to connect the clamp to the conduit would be to rotate the conduit-receiving element 9 about the shank 16 of the bolt 15 until the portion 10 would come into alignment with the conduit. Or, if the conduit approached the pipe from directions perpendicular to the direction of the pipe, it still could be'connected to the clamp by rotating the element 9 as before. If the conduit approached the pipe from a direction which would be in some other plane, it would then be necessary to rotate the entire assembly about the pipe 17 until the proper position isfreached and then rotating theelement 9 about the bolt 15 to bring the portion 10 in alignment with the conduit 24. This may be accomplished Without removing the clamp from the pipe or any of the parts of the clamp and having to replace them after the adjustment is made.

In Fig. 5 is shown a modification in which a U-bolt 25 is substituted for the S-bolt 15 and a separate carriage bolt 29, threaded at 28, is provided for connecting the conductor 23 to the clamp. In this modification, 'the hole 14 is square instead of round in order to prevent the bolt 29 from turning when the nut 30 is drawn up and tightened on it. The shanks 26 of the I U-bolt extend through the crescent-shaped recessesY 12 Vof the element 9 and the bolt is made to engage the pipe 17 I-lrmly by the nuts 27 which are drawn up and tightened on the shanks and also serve topclamp the conduit-receiving elemente against the clamping element 1. In this thereby eliminated.- The hole 22 is provided for the reception of a connecting bolt.

While I have shown only two embodiments of my invention for the purposes of illustration and description, other changes and modications may be made therein without departing from the scope of the invention and I, therefore, desire to be limited only by the scope of the appended claims.

I claim:

1. A ground clamp for connecting a conductor oan electric conduit to a grounding means, comprising arecessed clamping element having parallel recessed walls for receiving said grounding means, a conduit-receiving element having 11.5 an opening therein, and a. clamping bolt embracing/said grounding means and extending between sad walls and through said opening for attaching said elements together andV to said grounding means. i

2. In a ground clamp for connecting a conductor of an electric conduit to a grounding means, a clamping element having parallel recessed walls for receiving said grounding means and a base recessed at its sides for receiving a clamping U-bolt, the shanks of said bolt extending'between said walls, and a conduit-receiving element having arcuate side openings aligning respectively with said recesses for receiving said bolt,` whereby said conduit-receiving member may be rotated about said bolt.

3. In a ground clamp for connecting a conductor of an electric conduit to a grounding means, a clamping element having parallel recessed walls for receiving said grounding means 1" and a base recessed centrally for receiving a clamping S-bolt, the shank of said bolt extending between said Walls, and a conduit-receiving element having a central opening aligning With L said recess for receiving said bolt, whereby said l@ conduit-receiving member may be rotated about said bolt. y

JAMES MANGIN. 

